Recently, a display apparatus for displaying a stereoscopic image that human beings can recognize as a three-dimensional space by adopting a projection method using binocular parallax has been put into practical use. An example of such a display apparatus is a monitor for displaying a stereoscopic image that an observer can view stereoscopically with naked eyes using parallax images (e.g. nine parallax images) taken from a plurality of viewpoints using a light beam controller such as a lenticular lens, for example.
Medical image diagnosis apparatuses, such as an ultrasound diagnosis apparatus, an X-ray computed tomography (CT) apparatus, and a magnetic resonance imaging (MRI) apparatus, that can create three-dimensional medical image data (volume data) have been put into practical use. In the related art, the volume data created by the medical image diagnosis apparatuses becomes a two-dimensional image (a rendering image) through various kinds of image processing (rendering processing) and is displayed in two-dimensions on a general-purpose monitor.
For example, volume data created by a medical image diagnosis apparatus becomes a two-dimensional image (a volume rendering image) reflecting three-dimensional information through volume rendering, and is displayed in two-dimensions on a general-purpose monitor. However, the volume rendering image displayed on a two-dimensional display surface on the general-purpose monitor provides a feeling of shallow depth, whereby an observer can hardly determine whether an interested region is actually placed in the front side or the rear side.
Therefore, it is examined that the volume rendering image created by performing volume rendering from a plurality of viewpoints on the volume data created by the medical image diagnosis apparatus is displayed stereoscopically on a monitor capable of providing stereoscopic viewing. Because medical images require an image quality with contrast, “black” is generally used for a background color on medical images. In addition, for a background color of characters or other information displayed together with medical images, black is generally used. As a result, the feeling of the depth of medical images to be viewed stereoscopically may be reduced.